It seems strange, that text wrapping works only on desktop version of Excel. First, I found that wrapping doesn`t work in my LibreOffice, so I am interested in LibreOffice support mostly. But it seems to be a true bug, if it does not work even in Excel Online (loaden via OneDrive).
The fix must exist, because when I open 'cell properties', I see all formatting flags set: I just press OK (the wrapping is applied now) and save the document, load the file to the OneDrive and open with Excel Online to see styles applied.
The extracted files from .zip, created by openpyxl, are different from created in LibreOffice and Excel Online.
The text wrapping, created in Excel Online also works in LibreOffice, so in this case LibreOffice <=> Excel Online.
wb = Workbook() ws = wb.worksheets ws.title = "Sheet1" ws['A1'].alignment = Alignment(wrap_text=True) ws['A1'].value = "Some long \ntext to wrap\n in a cell" wb.save('wrap_text1.xlsx')
Openpyxl 2.5.0, python 3.6.4, Arch Linux